BJ Penn isn't just returning to the Octagon this Saturday for the fun of it. Penn wants nothing more than to stop the train that is Rory MacDonald.

The two will collide as part of the UFC On Fox: Henderson Vs. Diaz main card Saturday from Seattle. However, that didn't stop them from exchanging some choice words for one another during the pre-fight press conference on Thursday.

Check out the exchange between the former champion and the Canadian in the video below: